The present invention pertains to blade assemblies such as are used with bulldozers, snow plows, road graders and the like and, more particularly, to such blade assemblies including a readily detachable blade or cutting edge.
In my earlier U.S. Pat. No. 3,202,226, I provide a blade assembly with a detachable blade in which the moldboard has a plurality of openings or sockets and the blade has, on its rear face, a plurality of rearwardly projecting lugs. The sockets and lugs are of trapezoidal cross-section and permit the blade to be attached to the moldboard by inserting the lugs into the sockets, lowering the blade to seat the lugs and inserting wedges into the sockets to lock the blade in position on the moldboard. While this arrangement provides a substantial improvement over earlier systems in which bolts and nuts are employed to attach the blade to the moldboard, frequent difficulties are encountered in removing a worn blade from its moldboard. Frequently after prolonged use the blade will have developed a rearwardly extending burr or flange-like projection. Since removal of a worn blade involves a reverse sequence of operations relative to its installation, the rearwardly projecting burr presents a problem as it interfers with or prevents the lifting of the blade to free the lugs from the moldboard sockets.
U. S. Pat. No. 3,477,520 to Gray discloses a blade assembly in which detachable blades are provided with rearwardly projecting wedge blocks which engage apertures in the moldboard. An eyebolt connected between a hook projecting from the rear of the blade and a bracket mounted on the rear face of the moldboard is employed to shift the blade laterally bringing the wedge blocks into engagement with an edge of the apertures. The blade mounting arrangement, of Gray, however, does not eliminate the use of bolts and nuts which are frequently difficult to remove.
It is the primary object of the present invention to provide a moldboard and detachable blade assembly which, while retaining the advantages of easy assembly and simplicity of the assembly of my above mentioned patent, eliminates the difficulties encountered as a consequence of the formation of burrs on worn blades.
Another object of the present invention is the provision of a detachable blade assembly which is characterized by its simplicity of design and construction and by the small number of component parts.